https://doi.org/10.1140/epjc/s10052-013-2301-5
Regular Article - Experimental Physics
Measurement of the flavour composition of dijet events in pp collisions at 
with the ATLAS detector
1
CERN, 1211, Geneva 23, Switzerland
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School of Chemistry and Physics, University of Adelaide, Adelaide, Australia
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Physics Department, SUNY Albany, Albany, NY, United States of America
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Department of Physics, University of Alberta, Edmonton, AB, Canada
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Department of Physics, Ankara University, Ankara, Turkey
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Department of Physics, Dumlupinar University, Kutahya, Turkey
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Department of Physics, Gazi University, Ankara, Turkey
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Division of Physics, TOBB University of Economics and Technology, Ankara, Turkey
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Turkish Atomic Energy Authority, Ankara, Turkey
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LAPP, CNRS/IN2P3 and Université de Savoie, Annecy-le-Vieux, France
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High Energy Physics Division, Argonne National Laboratory, Argonne, IL, United States of America
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Department of Physics, University of Arizona, Tucson, AZ, United States of America
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Department of Physics, The University of Texas at Arlington, Arlington, TX, United States of America
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Physics Department, University of Athens, Athens, Greece
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Physics Department, National Technical University of Athens, Zografou, Greece
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Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan
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Institut de Física d’Altes Energies and Departament de Física de la Universitat Autònoma de Barcelona and ICREA, Barcelona, Spain
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Institute of Physics, University of Belgrade, Belgrade, Serbia
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Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
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Department for Physics and Technology, University of Bergen, Bergen, Norway
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Physics Division, Lawrence Berkeley National Laboratory and University of California, Berkeley, CA, United States of America
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Department of Physics, Humboldt University, Berlin, Germany
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Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland
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School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom
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Department of Physics, Bogazici University, Istanbul, Turkey
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Division of Physics, Dogus University, Istanbul, Turkey
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Department of Physics Engineering, Gaziantep University, Gaziantep, Turkey
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Department of Physics, Istanbul Technical University, Istanbul, Turkey
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INFN Sezione di Bologna, Bologna, Italy
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Dipartimento di Fisica, Università di Bologna, Bologna, Italy
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Physikalisches Institut, University of Bonn, Bonn, Germany
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Department of Physics, Boston University, Boston, MA, United States of America
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Department of Physics, Brandeis University, Waltham, MA, United States of America
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Universidade Federal do Rio De Janeiro COPPE/EE/IF, Rio de Janeiro, Brazil
35
Federal University of Juiz de Fora (UFJF), Juiz de Fora, Brazil
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Federal University of Sao Joao del Rei (UFSJ), Sao Joao del Rei, Brazil
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Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, Brazil
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Physics Department, Brookhaven National Laboratory, Upton, NY, United States of America
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National Institute of Physics and Nuclear Engineering, Bucharest, Romania
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University Politehnica Bucharest, Bucharest, Romania
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West University in Timisoara, Timisoara, Romania
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Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina
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Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
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Department of Physics, Carleton University, Ottawa, ON, Canada
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CERN, Geneva, Switzerland
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Enrico Fermi Institute, University of Chicago, Chicago, IL, United States of America
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Departamento de Física, Pontificia Universidad Católica de Chile, Santiago, Chile
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Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile
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Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
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Department of Modern Physics, University of Science and Technology of China, Anhui, China
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Department of Physics, Nanjing University, Jiangsu, China
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School of Physics, Shandong University, Shandong, China
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Laboratoire de Physique Corpusculaire, Clermont Université and Université Blaise Pascal and CNRS/IN2P3, Clermont-Ferrand, France
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Nevis Laboratory, Columbia University, Irvington, NY, United States of America
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Niels Bohr Institute, University of Copenhagen, Kobenhavn, Denmark
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INFN Gruppo Collegato di Cosenza, Arcavata di Rende, Italy
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Dipartimento di Fisica, Università della Calabria, Arcavata di Rende, Italy
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Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland
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The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
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Physics Department, Southern Methodist University, Dallas, TX, United States of America
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Physics Department, University of Texas at Dallas, Richardson, TX, United States of America
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DESY, Hamburg and Zeuthen, Germany
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Institut für Experimentelle Physik IV, Technische Universität Dortmund, Dortmund, Germany
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Institut für Kern- und Teilchenphysik, Technical University Dresden, Dresden, Germany
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Department of Physics, Duke University, Durham, NC, United States of America
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SUPA - School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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INFN Laboratori Nazionali di Frascati, Frascati, Italy
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Fakultät für Mathematik und Physik, Albert-Ludwigs-Universität, Freiburg, Germany
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Section de Physique, Université de Genève, Geneva, Switzerland
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INFN Sezione di Genova, Genova, Italy
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Dipartimento di Fisica, Università di Genova, Genova, Italy
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E. Andronikashvili Institute of Physics, Iv. Javakhishvili Tbilisi State University, Tbilisi, Georgia
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High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia
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II Physikalisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany
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SUPA - School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
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II Physikalisches Institut, Georg-August-Universität, Göttingen, Germany
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Laboratoire de Physique Subatomique et de Cosmologie, Université Joseph Fourier and CNRS/IN2P3 and Institut National Polytechnique de Grenoble, Grenoble, France
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Department of Physics, Hampton University, Hampton, VA, United States of America
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Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge, MA, United States of America
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Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
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Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
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ZITI Institut für technische Informatik, Ruprecht-Karls-Universität Heidelberg, Mannheim, Germany
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Faculty of Applied Information Science, Hiroshima Institute of Technology, Hiroshima, Japan
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Department of Physics, Indiana University, Bloomington, IN, United States of America
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Institut für Astro- und Teilchenphysik, Leopold-Franzens-Universität, Innsbruck, Austria
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University of Iowa, Iowa City, IA, United States of America
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Department of Physics and Astronomy, Iowa State University, Ames, IA, United States of America
88
Joint Institute for Nuclear Research, JINR Dubna, Dubna, Russia
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KEK, High Energy Accelerator Research Organization, Tsukuba, Japan
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Graduate School of Science, Kobe University, Kobe, Japan
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Faculty of Science, Kyoto University, Kyoto, Japan
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Kyoto University of Education, Kyoto, Japan
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Department of Physics, Kyushu University, Fukuoka, Japan
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Instituto de Física La Plata, Universidad Nacional de La Plata and CONICET, La Plata, Argentina
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Physics Department, Lancaster University, Lancaster, United Kingdom
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INFN Sezione di Lecce, Lecce, Italy
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Dipartimento di Matematica e Fisica, Università del Salento, Lecce, Italy
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Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom
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Department of Physics, Jožef Stefan Institute and University of Ljubljana, Ljubljana, Slovenia
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School of Physics and Astronomy, Queen Mary University of London, London, United Kingdom
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Department of Physics, Royal Holloway University of London, Surrey, United Kingdom
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Department of Physics and Astronomy, University College London, London, United Kingdom
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Laboratoire de Physique Nucléaire et de Hautes Energies, UPMC and Université Paris-Diderot and CNRS/IN2P3, Paris, France
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Fysiska institutionen, Lunds universitet, Lund, Sweden
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Departamento de Fisica Teorica C-15, Universidad Autonoma de Madrid, Madrid, Spain
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Institut für Physik, Universität Mainz, Mainz, Germany
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School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
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CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France
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Department of Physics, University of Massachusetts, Amherst, MA, United States of America
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Department of Physics, McGill University, Montreal, QC, Canada
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School of Physics, University of Melbourne, Victoria, Australia
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Department of Physics, The University of Michigan, Ann Arbor, MI, United States of America
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Department of Physics and Astronomy, Michigan State University, East Lansing, MI, United States of America
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INFN Sezione di Milano, Milano, Italy
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Dipartimento di Fisica, Università di Milano, Milano, Italy
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B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Republic of Belarus
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National Scientific and Educational Centre for Particle and High Energy Physics, Minsk, Republic of Belarus
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Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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Group of Particle Physics, University of Montreal, Montreal, QC, Canada
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P.N. Lebedev Institute of Physics, Academy of Sciences, Moscow, Russia
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Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia
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Moscow Engineering and Physics Institute (MEPhI), Moscow, Russia
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Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
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Fakultät für Physik, Ludwig-Maximilians-Universität München, München, Germany
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Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), München, Germany
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Nagasaki Institute of Applied Science, Nagasaki, Japan
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Graduate School of Science and Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Japan
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INFN Sezione di Napoli, Napoli, Italy
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Dipartimento di Scienze Fisiche, Università di Napoli, Napoli, Italy
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Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, United States of America
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Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen, Netherlands
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Nikhef National Institute for Subatomic Physics and University of Amsterdam, Amsterdam, Netherlands
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Department of Physics, Northern Illinois University, DeKalb, IL, United States of America
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Budker Institute of Nuclear Physics, SB RAS, Novosibirsk, Russia
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Department of Physics, New York University, New York, NY, United States of America
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Ohio State University, Columbus, OH, United States of America
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Faculty of Science, Okayama University, Okayama, Japan
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Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK, United States of America
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Department of Physics, Oklahoma State University, Stillwater, OK, United States of America
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RCPTM, Palacký University, Olomouc, Czech Republic
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Center for High Energy Physics, University of Oregon, Eugene, OR, United States of America
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LAL, Université Paris-Sud and CNRS/IN2P3, Orsay, France
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Graduate School of Science, Osaka University, Osaka, Japan
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Department of Physics, University of Oslo, Oslo, Norway
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Department of Physics, Oxford University, Oxford, United Kingdom
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INFN Sezione di Pavia, Pavia, Italy
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Dipartimento di Fisica, Università di Pavia, Pavia, Italy
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Department of Physics, University of Pennsylvania, Philadelphia, PA, United States of America
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Petersburg Nuclear Physics Institute, Gatchina, Russia
150
INFN Sezione di Pisa, Pisa, Italy
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Dipartimento di Fisica E. Fermi, Università di Pisa, Pisa, Italy
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Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, United States of America
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Laboratorio de Instrumentacao e Fisica Experimental de Particulas - LIP, Lisboa, Portugal
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Departamento de Fisica Teorica y del Cosmos and CAFPE, Universidad de Granada, Granada, Spain
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Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic
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Faculty of Mathematics and Physics, Charles University in Prague, Praha, Czech Republic
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Czech Technical University in Prague, Praha, Czech Republic
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State Research Center Institute for High Energy Physics, Protvino, Russia
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Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom
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Physics Department, University of Regina, Regina, SK, Canada
161
Ritsumeikan University, Kusatsu, Shiga, Japan
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INFN Sezione di Roma I, Roma, Italy
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Dipartimento di Fisica, Università La Sapienza, Roma, Italy
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INFN Sezione di Roma Tor Vergata, Roma, Italy
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Dipartimento di Fisica, Università di Roma Tor Vergata, Roma, Italy
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INFN Sezione di Roma Tre, Roma, Italy
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Dipartimento di Fisica, Università Roma Tre, Roma, Italy
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Faculté des Sciences Ain Chock, Réseau Universitaire de Physique des Hautes Energies - Université Hassan II, Casablanca, Morocco
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Centre National de l’Energie des Sciences Techniques Nucleaires, Rabat, Morocco
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Faculté des Sciences Semlalia, Université Cadi Ayyad, LPHEA, Marrakech, Morocco
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Faculté des Sciences, Université Mohamed Premier and LPTPM, Oujda, Morocco
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Faculté des sciences, Université Mohammed V-Agdal, Rabat, Morocco
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DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de l’Univers), CEA Saclay (Commissariat a l’Energie Atomique), Gif-sur-Yvette, France
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Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA, United States of America
175
Department of Physics, University of Washington, Seattle, WA, United States of America
176
Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
177
Department of Physics, Shinshu University, Nagano, Japan
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Fachbereich Physik, Universität Siegen, Siegen, Germany
179
Department of Physics, Simon Fraser University, Burnaby, BC, Canada
180
SLAC National Accelerator Laboratory, Stanford, CA, United States of America
181
Faculty of Mathematics, Physics & Informatics, Comenius University, Bratislava, Slovak Republic
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Department of Subnuclear Physics, Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovak Republic
183
Department of Physics, University of Johannesburg, Johannesburg, South Africa
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School of Physics, University of the Witwatersrand, Johannesburg, South Africa
185
Department of Physics, Stockholm University, Stockholm, Sweden
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The Oskar Klein Centre, Stockholm, Sweden
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Physics Department, Royal Institute of Technology, Stockholm, Sweden
188
Departments of Physics & Astronomy and Chemistry, Stony Brook University, Stony Brook, NY, United States of America
189
Department of Physics and Astronomy, University of Sussex, Brighton, United Kingdom
190
School of Physics, University of Sydney, Sydney, Australia
191
Institute of Physics, Academia Sinica, Taipei, Taiwan
192
Department of Physics, Technion: Israel Institute of Technology, Haifa, Israel
193
Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
194
Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece
195
International Center for Elementary Particle Physics and Department of Physics, The University of Tokyo, Tokyo, Japan
196
Graduate School of Science and Technology, Tokyo Metropolitan University, Tokyo, Japan
197
Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
198
Department of Physics, University of Toronto, Toronto, ON, Canada
199
TRIUMF, Vancouver, BC, Canada
200
Department of Physics and Astronomy, York University, Toronto, ON, Canada
201
Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
202
Department of Physics and Astronomy, Tufts University, Medford, MA, United States of America
203
Centro de Investigaciones, Universidad Antonio Narino, Bogota, Colombia
204
Department of Physics and Astronomy, University of California Irvine, Irvine, CA, United States of America
205
INFN Gruppo Collegato di Udine, Udine, Italy
206
ICTP, Trieste, Italy
207
Dipartimento di Chimica, Fisica e Ambiente, Università di Udine, Udine, Italy
208
Department of Physics, University of Illinois, Urbana, IL, United States of America
209
Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
210
Instituto de Física Corpuscular (IFIC) and Departamento de Física Atómica, Molecular y Nuclear and Departamento de Ingeniería Electrónica and Instituto de Microelectrónica de Barcelona (IMB-CNM), University of Valencia and CSIC, Valencia, Spain
211
Department of Physics, University of British Columbia, Vancouver, BC, Canada
212
Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
213
Department of Physics, University of Warwick, Coventry, United Kingdom
214
Waseda University, Tokyo, Japan
215
Department of Particle Physics, The Weizmann Institute of Science, Rehovot, Israel
216
Department of Physics, University of Wisconsin, Madison, WI, United States of America
217
Fakultät für Physik und Astronomie, Julius-Maximilians-Universität, Würzburg, Germany
218
Fachbereich C Physik, Bergische Universität Wuppertal, Wuppertal, Germany
219
Department of Physics, Yale University, New Haven, CT, United States of America
220
Yerevan Physics Institute, Yerevan, Armenia
221
Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules (IN2P3), Villeurbanne, France
* e-mail: atlas.publications@cern.ch
Received:
2
October
2012
Revised:
18
December
2012
Published online:
12
February
2013
This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at 
using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y|<2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
